Artificial leg



(No Model.) 4

J. FURRER. ARTIFICIAL LEG No. 592,542 Patented Oct. 26, 1897.

mlllnp.l gli TTEST.

Nrrn `Sfrnrns Arn'r JOSEPH FURRER, OF EAST TOLEDO, OHIO.

lARTIFICIAL LEG.

SPECIFICATION forming part of Letters Patent No. 592,542, dated October 26, 1897.

Application filed Apll 13, 1 89 7.

To all whom t may concern:

Beit known that I, JOSEPH FURRER, a citizen of the United States, residing at East Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in Artificial Legs; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

This invention relates to artificial legs, and has for its object to produce an improved leg in which the movement at the knee-joint will be free and natural and the lower portion of the leg returned to its normal position whenever the flexure of the leg is received.

To these ends myinvention consists in the features and in the combination, arrangement, and construction of parts hereinafter described, and specifically pointed out in the claims following the description, reference being had to the accompanying drawings, forming a part of'this specification, wherein- Figure l represents a side elevation of a portion of an artificial leg, illustrating the improved knee-joint; and Fig. 2 represents a vertical central section thereof.

Referring t-o the drawings, the numeral 1 indicates the middle member of the artificial leg, and 2 a portion of a leather socket in which the stump of the upper member of the leg is adapted to be fitted. To the socket 2 is rigidly secured a metallic frame 3, having a central downwardly-projecting eye 4. To the upper member 3 is rmly riveteda vertical metallic strap 5, terminating at its upper end in two coincident eyes 6, between which is fitted theeye et of the frame 3, said eyes being pivotally connected to each other by a pivot-pin 7.

The numeral S indicates a cross-arm which is pivotally attached between its ends to the lower portion of the strap and to the middle member of the leg by a bolt 9, over the outer threaded end of which is tappeda nut 10. The crossarm at its opposite ends is provided with upwardly-projecting lugs 1l and 12, the lugs at each end being in close prox- Serial No. 631,983. (No model.)

imity and slightly diverging. Similar lugs 13 and 14 project downwardly from the frame 3, but each of the pair of lugs 13 and 14 are arranged somewhat distant from one another. Coiled springs 15 and 1G are arranged over the lugs 1l, l2, 13, and 14:, and are placed thereon under sufficient compression to maintain the springs in place under all conditions.

In act of walking when the leg is bent at the knee the two members turn upon the pivot-pin 7, and as they turn relatively 011e to the other the cross-arm 8 oscillates from one side to the otherof a vertical line passing through said pivotal point, and the springs are thus placed under increased tension, whereby when the leg is lifted from the ground said springs operate to oscillate the cross-arm back to its normal position and thus return the middle member 'of the leg to a vertical position. The springs lexert a vertical thrust on the ends of the crossarm, and thus also exert a force to maintain the cross-arm in a horizontal position, while the springs l0, being oppositelyinclined, tend to act more directly in restoring the crossarm, and with it the middle member of the leg to its normal position.

The action of the springs is prompt, easy, and extremely natural and gives to the leg a motion closely approximating that of the human limb.

To the lower member 3 of the leg is articulated the foot 17 in the following manner: Attached to the lower member 3 are two straps 18, that embrace the opposite sides of the leg. The lower ends of the strap are united bya round cross-bar 19, that forms a journal, and the foot is pivotally mounted on said `cross-bar by two metallic straps 20, that are part of the leg is as follows:

In walking the middle member of the leg ICO between its ends to said middle member, andv springs arranged between the-oppositeends of said cross-arm and frame, substantially as described.

2. In an yartificial leg, the combinationwi'th the frame attached-to thezupper member-Of the leg and provided with downwardprojecting lugs,'of a metallicstrap iixed to the middle member and vpivotally connected to saidframe, a cross-arm'pivoted between its ends to said middle member and provided with upwardly-projecting,lugs at its opposite ends, and coiled springs itted at their opposite ends over the said lugs on the frame andcross-arm, substantially as described.

3. The combination with an artificial leg of yan artificial foot articulated thereto and having a rocking motion thereon, a coiled spring arranged in a longitudinal recess in the lsole of ythe foot, and a tang Xed to the leg and projecting down between the convo- `lutions `of the spring, substantially as described and for the purpose specified.

In testimony whereof vI affiXmy-signature in presence of two witnesses.

JOSEPH QFURRER.

Witnesses:

vGOTTLIEB BAUMG-AERTNER, FORD SCHEETS. 

